49 research outputs found
High-resolution laser system for the S3-Low Energy Branch
In this paper we present the first high-resolution laser spectroscopy results
obtained at the GISELE laser laboratory of the GANIL-SPIRAL2 facility, in
preparation for the first experiments with the S-Low Energy Branch. Studies
of neutron-deficient radioactive isotopes of erbium and tin represent the first
physics cases to be studied at S. The measured isotope-shift and hyperfine
structure data are presented for stable isotopes of these elements. The erbium
isotopes were studied using the atomic transition (415 nm) and the tin isotopes were studied by
the atomic transition (286.4
nm), and are used as a benchmark of the laser setup. Additionally, the tin
isotopes were studied by the
atomic transition (811.6 nm), for which new isotope-shift data was obtained and
the corresponding field-shift and mass-shift factors are
presented
Anti-Inflammatory Effect of Fluvastatin on IL-8 Production Induced by Pseudomonas aeruginosa and Aspergillus fumigatus Antigens in Cystic Fibrosis
International audienceBACKGROUND: Early in life, patients with cystic fibrosis (CF) are infected with microorganisms including bacteria and fungi, particularly Pseudomonas aeruginosa and Aspergillus fumigatus. Since recent research has identified the anti-inflammatory properties of statins (besides their lipid-lowering effects), we investigated the effect of fluvastatin on the production of the potent neutrophil chemoattractant chemokine, IL-8, in whole blood from CF patients, stimulated by Pseudomonas aeruginosa (LPS) and Aspergillus fumigatus (AFA) antigens. RESULTS: Whole blood from adult patients with CF and from healthy volunteers was collected at the Rennes University Hospital (France). Blood was pretreated for 1 h with fluvastatin (0-300 µM) and incubated for 24 h with LPS (10 µg/mL) and/or AFA (diluted 1/200). IL-8 protein levels, quantified by ELISA, were increased in a concentration-dependent manner when cells were stimulated by LPS or AFA. Fluvastatin strongly decreased the levels of IL-8, in a concentration-dependent manner, in whole blood from CF patients. However, its inhibitory effect was decreased or absent in whole blood from healthy subjects. Furthermore, the inhibition induced by fluvastatin in CF whole blood was reversed in the presence of intermediates within the cholesterol biosynthesis pathway, mevalonate, farnesyl pyprophosphate or geranylgeranyl pyrophosphate that activate small GTPases by isoprenylation. CONCLUSIONS: For the first time, the inhibitory effects of fluvastatin on CF systemic inflammation may reveal the important therapeutic potential of statins in pathological conditions associated with the over-production of pro-inflammatory cytokines and chemokines as observed during the manifestation of CF. The anti-inflammatory effect could be related to the modulation of the prenylation of signalling proteins
SarcoĂŻdose pulmonaire apparue sous Ă©tanercept [Pulmonary sarcoidosis developing during treatment with etanercept]
International audienceINTRODUCTION: TNF blockers are widely used to treat inflammatory rheumatic diseases and also in the treatment of extrapulmonary sarcoidosis. TNFα plays a major role in the development and persistence of sarcoid granulomata. However, recent studies have reported the involvement of anti-TNF therapies in the development of granulomatosis associated with the clinical and radiological features of sarcoidosis. CASE REPORT: A 54-years-old man with ankylosing spondylitis was treated with etanercept for two years. He was admitted with symptoms of bronchitis associated with radiological evidence of bilateral pulmonary nodules and a right upper lobe infiltrate. Anti-TNF therapy was stopped even though the patient had received 3 months of prophylactic treatment with rifampicin and isoniazid before starting etanercept. Bronchoalveolar lavage excluded infection, particularly tuberculosis. The chest CT-scan showed bilateral pulmonary nodules with peribronchovascular micronodules and enlarged mediastinal lymph nodes. Surgical lung biopsy was performed and revealed non-caseating granulomata. All the data were consistent with a diagnosis of pulmonary sarcoidosis. The patient remained symptomatic despite discontinuation of etanercept for ten months. Corticosteroids were then introduced, leading to a clinical, functional and radiological improvement. CONCLUSION: This case report underlines the importance of studying the pulmonary complications of TNF blockers. The first priority is to exclude tuberculosis but a diagnosis of sarcoid-like granulomatosis has to be considered. Twenty-three cases have been described in the literature to date
Une cause rare de maladie kystique pulmonaire : maladie à dépôts de chaînes légères d'immunoglobuline. [An unusual cause of cystic lung disease: Light chain deposition disease].
International audienceINTRODUCTION: Light chain deposition disease is a rare clinical entity characterized by deposition of monoclonal immunoglobulin light chains in organs. The kidneys are almost always affected, while the lung manifestations that have been reported, including nodular or diffuse disease, especially cystic lesions, are unusual. CASE REPORT: We report the case of a 60-year-old man with a diffuse infiltrative lung disease characterized by numerous apical cysts. The diagnosis of light chain deposition cystic lung disease was obtained by surgical lung biopsy. Light chain deposits in the salivary glands were the only extrapulmonary manifestation. Despite 12Â chemotherapy cycles, the patient's lung function and radiological appearances worsened. CONCLUSION: This is the fourth case describing a cystic lung disease due to light chain deposition in the literature. It highlights the need for comprehensive investigations so as not to miss this rare cause of cystic lung disease, which appears to be related to a primary pulmonary lymphoproliferative disorder. The only treatment that appears to be effective is lung transplantation
Contacting n poly-Si junctions with fired AZO layers: a promising approach for high temperature passivated contact solar cells
International audiencePolysilicon (poly-Si) based passivating contacts are promising to improve silicon solar cells conversion efficiency. However, the use of Transparent Conductive Oxides (TCO) has to be considered to improve lateral conductivity while maintaining good optical and surface passivation properties especially for bifacial devices. In this work different Aluminum-doped Zinc Oxide (AZO) based layers have been investigated after high temperature firing steps to contact Phosphorus-doped poly-Si layers. Contact resistivity below 100 mΩ.cm at the AZO/n poly-Si interface and stable implied open circuit voltage values (> 715 mV) have been obtained for firing temperatures from 550°C to 900°C. Moreover, the use of capping layers allows to maintain highly conductive AZO layers upon annealing. This novel high temperature contacting method via indium-free TCOs, is particularly interesting for the industrial integration of poly-Si based passivated contacts and provides new perspectives for advanced homojunction solar cells
Experimental study and numerical modelling of high temperature
International audience12 13 Two pilot-scale regenerative heat storage systems have been tested by the French Alternative Energies and Atomic 14 Energy Commission (CEA). The first one is a 1.1-MWhth structured packed bed consisting of ceramic plates forming 15 corrugated channels. The second one is a 1.4-MWhth granular packed bed consisting of basaltic rocks enclosed by refractory 16 walls. The two regenerators were tested over a hundred of thermal cycles between 80°C and 800°C with different fluid mass 17 flows. Both systems showed their ability to store heat efficiently and to provide thermal energy at a stable temperature for the 18 most part of the discharge process. The granular packed bed exhibited large transverse thermal heterogeneities due to flow 19 channelling in the corners of the cross section. However, this phenomenon appears not to have degraded significantly the 20 thermal performances, and the average one-dimensional thermal behaviour of the system may be assessed thanks to the surface 21 weighted average of the temperature over the bed cross section. Compared to the granular packed bed, the structured bed 22 showed comparable thermal performances while inhibiting flow heterogeneities and reducing by up to 54% the average 23 pressure drop. Furthermore, at the end of the test campaign, the packed beds were observed and compared from a mechanical 24 point of view. The thermal results were successfully simulated over numerous charge/discharge cycles thanks to a one-25 dimensional numerical model. This is significant since the discrepancies between experimental and numerical results are likely 26 to accumulate from a cycle to the other. The model considers the packed beds as continuous and homogeneous porous media 27 but takes account of the conduction resistances within the solid filler and the walls. The pressure drop of the beds was 28 computed using a correlation developed thanks to a previous CFD study for the structured packed bed, and the Ergun equation 29 for the granular packed bed. Compared to experimental data, these correlations enabled to estimate the order of magnitude and 30 the evolution trend of the pressure drop with an average deviation ranging from-7.2% to +61.9%. For the granular packed bed, 31 these deviations are ascribed to the flow heterogeneities and the shape of the rocks which are not taken into account in the 32 Ergun equation. 33 34 In order to tackle fossil fuel depletion and climate change, the renewable energy share in the energy mix has to be 40 increased, especially for electricity generation (IPCC, 2014). However, some promising renewable energy sources like wind 41 and solar are intermittent. That's why energy storage is one of the technical solutions enabling the development of a 42 continuous and controllable renewable energy supply. 43 Nowadays, electricity storage is largely dominated by Pumped Hydroelectric Energy Storage since this technology is 44 mature and offers low loss storage capacities. However, it has a very low energy and power density (Sabihuddin et al., 2015), 45 and requires specific locations with high altitude difference to be implemented. That's why this technology is unlikely to 46 respond the increasing need for large scale energy storage. Several promising alternative technologies have been proposed like 47 Adiabatic Compressed Air Energy Storage (Hartmann et al., 2012; Sciacovelli et al., 2017a), Pumped Thermal Energy Storage 48 (Desrues et al., 2010; Garvey et al., 2015), Liquid Air Energy Storage (Sciacovelli et al., 2017b) and Thermal Energy Storage 49 in Concentrated Solar Power (CSP) plants (to shift the conversion of heat into electricity). In all these thermodynamic 50 processes, there is a need for large scale Thermal Energy Storage systems. It is preferable to store/recover the energy at very 51 high or very low temperature (for Pumped Thermal Energy Storage and Liquid Air Energy Storage) to ensure good 52 thermodynamic efficiency. Regenerative sensible heat storage using gas (usually air) as heat transfer fluid is a relevant and 53 mature technology which meets this requirement. 54 It consists in storing sensible heat in a solid packed bed enclosed in an insulated tank. The packed bed may be either 55 granular or structured. The thermal energy is conveyed by a gaseous heat transfer fluid in direct contact with the solid. During 56 charging process, the hot fluid is injected by the top of the tank, heats the solid and exits at cold temperature from the bottom. 57 To discharge the system, the flow is inverted: the cold fluid is injected by the bottom, is heated up by the solid and exits at hot 58 temperature from the top. Thanks to buoyancy forces, this configuration preserves thermal stratification with hot and cold 59 regions well separated by a thermal gradient as stiff as possible. 60 This technology is already used in steel and glass industries (to preheat air in blast furnaces), and in industrial air 61 purification systems. However, to use it in the above mentioned thermodynamic processes, the design and the operation 62 strategy should be adapted to each particular case to ensure optimal performances. This optimization requires numerical 63 models validated with experimental data obtained on representative pilot-scale setups. 6
Modelling clay rock behaviour from macro to micro scales (and back): deformation, rupture, and hydromechanical phenomena
Absence de récidive sous adalimumab, chez une patiente ayant présenté un asthme induit par l’infliximab
National audienceIntroduction Les cas d’asthmes induits par les anti-TNF-α sont rares, et il n’a jamais été décrit de tentative de réintroduction d’une molécule de même classe. Il n’existe pas de recommandations concernant la conduite à tenir dans ces situations. Observation Nous rapportons le cas d’une femme de 45 ans, non-fumeuse, sans antécédent personnel d’asthme, qui était atteinte d’une maladie de Crohn depuis l’adolescence. En 2009, elle a été traitée par infliximab. La réponse digestive a été rapidement efficace, cependant après 4 semaines de traitement, elle commençait à présenter une toux sèche associée à une dyspnée inhabituelle. Ces symptômes évocateurs d’hyperréactivité bronchique s’aggravèrent progressivement, et les explorations fonctionnelles respiratoires confirmèrent le diagnostic d’asthme. Malgré des traitements adaptés, la sévérité de la situation imposa l’arrêt de l’infliximab. L’asthme s’est alors amélioré, mais en raison de l’atteinte digestive un nouveau traitement dut être débuté : l’adalimumab, sans rechute d’asthme à ce jour. Conclusion Ce cas clinique met en évidence la possibilité de réintroduire un nouvel anti-TNF-α après un premier épisode d’asthme induit par cette classe médicamenteuse. Cette option pourrait être extrêmement utile chez les patients présentant des atteintes sévères (polyarthrite rhumatoïde, maladies inflammatoires chroniques de l’intestin) en l’absence d’alternative thérapeutiqu